noun
Historical term for the lord of a feudal domain (han) during the Edo period. Refers specifically to the ruler of a han, distinct from the broader term 大名 (daimyo), which can include lords without a domain.
江戸時代、各藩の藩主は参勤交代で江戸に滞在した。
During the Edo period, the feudal lords of each domain stayed in Edo under the sankin-kōtai system.
この城はもともと地元の藩主の居城だった。
This castle was originally the residence of the local feudal lord.
大名 is a broader term for a feudal lord, while 藩主 specifically refers to the lord of a han (domain). All 藩主 are 大名, but not all 大名 are 藩主.
Compound of 藩 (han, 'feudal domain') and 主 (shu, 'lord, master'). The term became common in the Edo period to denote the ruler of a han.